U.S. Pat. No. 4,251,648 discloses curing copolymers of an epihalohydrin, an unsaturated glycidyl ether, and optionally, ethylene oxide, with a peroxide, a group IA, IIA, or IVA acid acceptor compound, and optionally, certain polyfunctional unsaturated compounds. While this cure system represented an improvement over prior art systems, a less expensive system is desired.